The present invention relates to solar panel shutdown techniques, and in particular, to solar panel shutdown techniques providing extra reliability to reduce fire hazards.
One issue with rooftop photovoltaic power generation systems is that solar panels generate voltages whenever the sun shines on them. Panels are frequently connected in series, and the combined voltage can reach several hundred volts. This can be problematic when it is desired to, for example, fight fires without the danger of electrocution. For this reason it is necessary to remove hazardous voltage from the solar array.
Typical fire safety shutdown systems use semiconductor devices as the active switching element to perform the function described above. It is safer to design a system that will remain engaged even if fire damage severs any connection to control electronics.